Evaluation of atmospheric sources of PCDD/Fs, PCBs and PBDEs around a steel industrial complex in northeast China using passive air samplers

The concern about emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) from steel industrial parks has increased in the past decades. In this study, polyurethane foam (PUF)-disk based passive air samples were collected in and around a big steel industrial park of Anshan, Northeast China from June 2008 to March 2009. The levels, seasonal variations and potential sources of PCDD/Fs, PCBs and PBDEs in the atmosphere around the steel industrial complex were investigated, and potential contribution of these three groups of persistent organic pollutants (POPs) from iron and steel production was also assessed. The air concentrations of ∑₁₇PCDD/Fs (summer: 0.02-2.77 pg m⁻³; winter: 0.20-9.79 pg m⁻³), ∑₁₉PCBs (summer: 23.5-155.8 pg m⁻³; winter: 14.6-81.3 pg m⁻³) and ∑₁₃PBDEs (summer: 2.91-10.7 pg m⁻³; winter: 1.10-3.89 pg m⁻³) in this targeted industrial park were relatively low in comparison to other studies, which implied that the industrial activities of iron and steel had not resulted in serious contamination to the ambient air in this area. On the whole, the air concentrations of PCDD/Fs in winter were higher than those of summer, whereas the concentrations of PCBs and PBDEs showed opposite trends. The result from principal component analysis indicated that coal combustion might be the main contributor of PCDD/F sources in this area.     

Atmospheric concentrations, occurrence and deposition of persistent organic pollutants (POPs) in a Mediterranean coastal site (Etang de Thau, France)

Atmospheric concentrations and deposition fluxes of PCDD/F and PCB have been evaluated over a 1-year period in a Mediterranean coastal lagoon (Etang de Thau, France). Indicative PBDE air concentrations in the hot season are also reported in this work. ∑2,3,7,8-PCDD/Fs and ∑18PCBs (gas + particulate) air concentrations ranged from 67 to 1700 fg m⁻³ and from 13 to 95 pg m⁻³, respectively whereas ∑8PBDEs (gas + particulate) summer time levels varied from 158 to 230 pg m⁻³. The PCDD/F and PCB atmospheric occurrence over Thau lagoon and subsequent inputs to the surface waters are determined by an assemble of factors, being the seasonality of atmospheric concentration, the air mass origin and meteorological conditions important drivers. Total (wet + dry) ∑2,3,7,8-PCDD/Fs and ∑18PCBs deposition fluxes to Thau Lagoon waters are 117 and 715 pg m⁻² d⁻¹, respectively.     

A proposal for a diet-based local PCDD/F deposition limit

This study proposes a method to estimate the maximal tolerable value for the atmospheric deposition of dioxins (PCDD/Fs) to soil. The case study for the application of this methodology is an Alpine valley where a steel production plant is present. In order to estimate the limit value for the PCDD/F deposition, consolidated food chain models were applied, but were adapted to be run backwards with respect to their original formulation, by starting from the diet of people living in the region and from the PCDD/F Tolerable Daily Intake value proposed by the World Health Organization. For this case study, the estimated limit value was 2.30 pg WHO-TEQ m⁻² d⁻¹ when only local diary products were taken into account and 1.91 pg WHO-TEQ m⁻² d⁻¹ when also the role of local cereals and vegetables was considered. The average PCDD/F deposition measured in the same region during a monitoring campaign was lower than the above limit values (1.40 pg WHO-TEQ m⁻² d⁻¹). Indications on how to consider the contribution of meat and fish are provided too. The approach proposed in this paper represents a useful tool to assess the acceptable overall deposition for a specific region.     

Polychlorinated dibenzo-p-dioxin and dibenzofuran in urban air of an Andean city

Particle-bound polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in ambient air were monitored together with particulate matter less than 10 μm (PM₁₀) at three sampling sites of the Andean city of Manizales, Colombia; during September 2009 and July 2010. PCDD/Fs ambient air emissions ranged from 1 fg WHO-TEQ m⁻³ to 52 fg WHO-TEQ m⁻³ in particulate fraction. The PM₁₀ concentrations ranged from 23 μg m⁻³ to 54 μg m⁻³. Concentrations of PM₁₀ and PCDD/Fs in ambient air observed for Manizales - a medium sized city with a population of 380 000 - were comparable to concentrations in larger cities. The highest concentrations of PCDD/Fs and PM₁₀ found in this study were determined at the central zone of the city, characterized by public transportation density, where diesel as principal fuel is used. In addition, hypothetical gas fractions of PCDD/Fs were calculated from theoretical K_p data. Congener profiles of PCDD/Fs exhibited ratios associated with different combustion sources at the different sampling locations, ranging from steel recycling to gasoline and diesel engines. Taking into account particle and gas hypothetical fraction of PCDD/Fs, Manizales exhibited values of PCDD/Fs equivalent to rural and urban-industrial sites in the southeast and center of the city respectively. Poor correlation of PCDDs with PM₁₀ (r = −0.55 and r = 0.52) suggests ambient air PCDDs were derived from various combustion sources. Stronger correlation was observed of PCDFs with PM₁₀. Poor correlation between precipitation and reduced PM₁₀ concentration in ambient air (r = −0.45) suggested low PM₁₀ removal by rainfall.     

Deposition fluxes of PCDD/Fs in a reservoir system in northern Taiwan

In this study, polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) concentrations and depositions in ambient air, water column and sediment were measured at a coupled reservoir-watershed system in northern Taiwan. The atmospheric PCDD/F concentration measured in the vicinity of the reservoir ranged from 4.9 to 39 fg I-TEQ m⁻³ and the Asian dust storm in February accounted for the peak value, which corresponded to a total suspended particle concentration of 128 μg m⁻³. The atmospheric PCDD/F deposition ranged from 1.4 to 19 pg I-TEQ m⁻² d⁻¹, with higher deposition occurring during winter and spring (long-range transport events). During summer, when atmospheric deposition is lower, consecutive tropical cyclones (typhoons) bring heavy rainfall that enhances soil erosion and creates turbidity-driven intermediate flow. This results in significantly higher PCDD/F deposition in water column of the reservoir at 70 m water depth (179 pg I-TEQ m⁻² d⁻¹) than at 20 m (21 pg I-TEQ m⁻² d⁻¹) during typhoon event. The accumulation rate of PCDD/Fs (9.1 ng I-TEQ m⁻² y⁻¹) in the reservoir sediments (depth: 0-2 cm) was consistent with PCDD/F deposition obtained from water column (6.1 and 8.3 ng I-TEQ m⁻² y⁻¹); however, it is significantly higher when compared to the atmospheric deposition (2.0 ng I-TEQ m⁻² y⁻¹). Based on the mass balance between the measurements of atmospheric deposition and sinking particles in water column, around 54-74% of PCDD/F inputs into the reservoir were contributed by the catchment erosion during normal period. However, the PCDD/F input contributed by the enhanced catchment erosion significantly increased to 90% during intensive typhoon events.     

Nationwide monitoring of atmospheric PCDD/Fs and dioxin-like PCBs in South Korea

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) were measured in ambient air samples collected from different parts of South Korea in 2008, and the measured levels were used for assessing the spatial and temporal distribution of atmospheric PCDDFs and DL-PCBs in South Korea. The average concentrations of atmospheric PCDD/Fs and DL-PCBs among the 37 sites were 28 fg I-TEQ m⁻³ (ND ∼ 617) and 1 fg WHO-TEQ m⁻³ (ND ∼ 0.016). Elevated atmospheric levels of PCDD/Fs and DL-PCBs observed at residential/industrial sites and in the north-west of Korea, indicated a potential contribution and impacts of anthropogenic sources of PCDD/Fs and DL-PCBs. These levels were similar or lower than those previously reported in other ambient air surveys. Average concentrations of PCDD/Fs showed small seasonal variations (ANOVA analysis, p = 0.144). The highest concentrations of PCDD/Fs were observed during winter, followed by spring, autumn and summer. Atmospheric PCDD/Fs and DL-PCBs in South Korea rapidly decreased during the last 10 years (1998-2008), demonstrating the efficiency of stricter regulations and the application of best available technologies/best environmental practices at emission sources. Comparison of the congener profiles and principal component analysis showed that current atmospheric PCDD/Fs are mostly influenced by industrial sources and PCBs from old commercial PCB uses. Nationwide POPs monitoring will continue and allows an effective evaluation of the implementation of the Stockholm Convention on POPs.     

Sources of PCDD/Fs, non-ortho PCBs and PAHs in sediments of high and low impacted transboundary rivers (Belgium-France)

PAHs, PCDD/Fs and non-ortho PCBs have been assessed in Yser and Upper-Scheldt river sediments. Higher contamination levels were observed in the Upper-Scheldt sediments: maximum concentrations for the 16 US-EPA PAHs, PCDD/Fs and non-ortho PCBs respectively amount to 8.9 mg kg⁻¹, 12 ng TEQ kg⁻¹ and 5.1 ng TEQ kg⁻¹. Diagnostic PAH ratios in sediments and atmospheric samples suggest that the PAH compounds are from pyrolytic origin, more specifically combustion processes. The huge consumption of coal in cokes-ovens and smelters and its use for house-heating in Northern France, although decreasing during the last decades, are in support of that suggestion. PCDD/F fingerprints in sediments and deposition material indicate that OCDD is the dominant congener. In addition use of pentachlorophenol (PCP) in the past led to a minor contribution of PCDD/Fs in our sediment samples. Non-ortho PCBs form a substantial fraction of the total TEQ concentrations observed in the sediments. Since the 1980s and 1990s a substantial reduction of the PCDD/F sediment concentrations is observed, but this is not the case for the PAHs.     

Atmospheric deposition of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in Guangzhou,China

Atmospheric deposition of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) was investigated at four locations, namely at Yuancun, Wushan, Haizhu and Changban in Guangzhou City, Guangdong Province. The annual deposition fluxes of tetra- to octa-CDD/Fs (total PCDD/Fs) were found to range from 170 to 3000 (mean 1500) pg m⁻² day⁻¹, and the fluxes of total 2, 3, 7, 8-substituted PCDD/F congeners ranged from 2.1 to 41 (mean 20) pg WHO-TEQ m⁻² day⁻¹ at Wushan. The average deposition fluxes of total 2, 3, 7, 8-substituted PCDD/F congeners in rainy season were found to be 37, 27 and 28 pg WHO-TEQ m⁻² day⁻¹ at Yuancun, Haizhu and Changban, respectively, and the PCDD/F deposition fluxes behaved obviously higher in rainy season than in dry season. Results from regression analysis showed that number of rainy days, the amount of wet precipitation, PCDD/F concentrations in particles and organic carbon content played important roles in the variation of PCDD/F deposition fluxes. Monthly average temperatures change little over the year. Therefore, it only played a minor role in monthly variation of PCDD/F deposition fluxes. Particle deposition fluxes were generally not considered as the factor that could cause the differences in PCDD/F deposition fluxes between rainy and dry season, but were found to be related with PCDD/F deposition fluxes in rainy season or dry season. It was found that the profiles of PCDD/F homologs or congeners in the samples were the same either spatially or temporally, indicating that the PCDD/F emission sources were similar to one another. The similarities in PCDD/F homolog patterns and the differences in deposition fluxes between samples collected from heavy-traffic roadside and nearby residence house roof indicated that vehicle exhaust might be an important source for PCDD/F in Guangzhou. PCDD/F concentrations and profiles of PCDD/F homologs in atmospheric deposition were compared with those in both total suspended particles in air and soils, and conclusions indicated that atmospheric deposition possibly tended to remove lower-chlorinated DD/Fs from air and was one of sources for PCDD/Fs in soils.     

Polycyclic aromatic hydrocarbon (PAH) deposition to and exchange at the air-water interface of Luhu, an urban lake in Guangzhou, China

Urban lakes are vulnerable to the accumulation of semivolatile organic compounds, such as PAHs from wet and dry atmospheric deposition. Little was reported on the seasonal patterns of atmospheric deposition of PAHs under Asian monsoon climate. Bulk (dry + wet) particle deposition, air-water diffusion exchange, and vapour wet deposition of PAHs in a small urban lake in Guangzhou were estimated based on a year-round monitoring. The total PAH particle deposition fluxes observed were 0.44-3.46 μg m⁻² day⁻¹. The mean air-water diffusive exchange flux was 20.7 μg m⁻² day⁻¹. The vapour deposition fluxes of PAHs ranged 0.15-8.26 μg m⁻² day⁻¹. Remarkable seasonal variations of particulate PAH deposition, air-water exchange fluxes and vapour wet deposition were influenced by seasonal changes in meteorological parameters. The deposition fluxes were predominantly controlled by the precipitation intensity in wet season whereas by atmospheric concentration in dry season.     

Formation of dioxins during exposure of pesticide formulations to sunlight

Chlorinated pesticides can contain impurities of dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and their precursors, as a result of various manufacturing processes and conditions. As precursor formation of PCDD/Fs can also be mediated by ultraviolet light (UV), this study investigated whether PCDD/Fs are formed when currently used pesticides are exposed to natural sunlight. Formulations containing pentachloronitrobenzene (PCNB; n = 2) and 2,4-dichlorophenoxyacetic acid (2,4-D; n = 1) were exposed to sunlight in quartz tubes, and the concentration of 93 PCDD/F congeners were monitored over time. Considerable formation of PCDD/Fs was observed in both PCNB formulations (by up to 5600%, to a maximum concentration of 57 000 μg ∑PCDD/F kg⁻¹) as well as the 2,4-D formulation (by 3000%, to 140 μg ∑PCDD/F kg⁻¹). TEQ also increased by up to 980%, to a maximum concentration of 28 μg kg⁻¹ in PCNB, but did not change in the 2,4-D formulation. Assuming similar yields as observed in the present study as a worst case scenario the use of PCNB in Australia may result in the formation of 155 g TEQ annum⁻¹, contributed primarily by OCDD formation. This warrants detailed evaluations on the contemporary release of PCDD/Fs to the environment after the use of pesticides. Changes in congener profiles (including the ratio of PCDDs to PCDFs (DF ratio)) suggest that pesticide sources of PCDD/Fs after sunlight exposure may not be recognized based on matching source fingerprints established from manufacturing impurities. These changes also provide preliminary insights into the possible formation routes and types of precursors involved.     

Transport of chlorinated dioxins and furans in soil columns: modeling pentachlorophenol pole-treating oil influence

Column experiments were conducted to validate a screening model predicting the influence of pentachlorophenol (PCP) pole-treating oil on the vertical migration of its impurities, chlorinated dioxins and furans (PCDD/Fs). PCP pole-treating oil (15 mL d⁻¹) and water (20 mL d⁻¹) were added daily to the top of sand and organic soil columns during 35 d. Column soil samples were analyzed to determine concentrations of hydrocarbons and PCDD/Fs at several depths in the columns (0-30 cm) and their evolution in time (7, 14, 21 and 35 d).The model predicted a significant vertical migration of PCDD/Fs due to the presence of oil as a free phase and PCDD/Fs were found in the different column layers at concentrations consistent with model predictions (same order of magnitude). Measured PCDD/Fs concentrations are in total disagreement with literature data and with model prediction in the absence of oil free phase, which implies PCDD/F properties alone cannot be used to predict their fate in the current context: the influence of PCP pole-treating oil must be accounted for to properly explain their migration.     

Analysis of PCDD/Fs and dioxin-like PCBs in atmospheric deposition samples from the Flemish measurement network: correlation between the CALUX bioassay and GC-HRMS

Since the CALUX (Chemically Activated LUciferase gene eXpression) bioassay is a fast, sensitive and inexpensive tool for the analysis of a high number of samples, the use of this technique in routine analysis of atmospheric deposition samples may be a valuable alternative for GC-HRMS. In this study, a validated CALUX method was used for the analysis of PCDD/Fs and dioxin-like PCBs in more than 90 atmospheric deposition samples for different locations in Flanders. The samples were taken in residential and agricultural areas, where a threshold limit of 21 pg WHO-TEQ m⁻² d⁻¹ for the sum of PCDD/Fs and dioxin-like PCBs was set, and in industrial zones and natural reserves, where no official threshold limit is available. The results from the Flemish measurement program showed correlation between CALUX and GC-HRMS for all the samples, originating from the different areas (R² of 0.81, 0.53 and 0.64 for dl-PCBs, PCDD/Fs and sum of both fractions, respectively). Median CALUX/GC-HRMS ratios of 2.0, 0.9 and 1.3 were reported for the PCDD/Fs, dioxin-like PCBs and the sum of both fractions, respectively. The results show that the CALUX bioassay is a valuable alternative tool for the classic GC-HRMS analysis of atmospheric deposition samples in the Flemish measurement network.     

Estimation and characterization of PCDD/Fs and dioxin-like PCBs from Chinese iron foundries

The iron foundry industry is considered to be a potential source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). This study investigated the emission factors and total emission amounts of PCDD/Fs and dioxin-like polychlorinated biphenyls (DL-PCBs) from iron foundries in China. The concentrations and the World Health Organization toxicity equivalents (WHO-TEQs) are presented and the congener profiles are discussed in this paper.In the present work, 26 fly ash samples were collected and tested to quantify the PCDD/Fs and DL-PCBs generated by 14 plants of different scales, and five stack gas samples were collected from two (named as EFG and LFG) of those plants. The emission levels of PCDD/Fs and DL-PCBs indicated that hot-air cupolas had lower emissions than cold-air cupolas. When iron ore lump and sinter were used as raw material, the emission factors were about 250 ng TEQ t⁻¹ of product. However, if the raw material was scrap, the emission factors varied owing to the different contents of organic materials in the raw materials. It was found that the mean WHO-TEQ values of PCDD/Fs and DL-PCBs were 144 and 34.2 pg Nm⁻³ in stack gas and 20.0 and 1.58 pg g⁻¹ in fly ash. In multiple tests, it was estimated that the mean emission factors of PCDD/Fs and DL-PCBs were 365 and 10.9 ng WHO-TEQ t⁻¹ released to residue and 2719 and 555 ng TEQ t⁻¹ released to air. The total emission amounts of PCDD/Fs and DL-PCBs from Chinese iron foundries with cupola furnaces released to residue and air were 16.8 and 146 g WHO-TEQ in 2008, respectively.     

Analysis of PCDD/Fs and dioxin-like PCBs in atmospheric deposition samples from the Flemish measurement network: Optimization and validation of a new CALUX bioassay method

Since the CALUX (Chemically Activated LUciferase gene eXpression) bioassay is a fast, sensitive and inexpensive tool for the analysis of a high number of samples, validation of new methods is urgently needed. In this study, a new method for the analysis of PCDD/Fs and dioxin-like PCBs in atmospheric deposition samples with the CALUX bioassay was developed, optimized and validated. The method consists of 4 steps: filtration, extraction, clean up and bioassay analysis. To avoid the use of large amounts of toxic solvents, new techniques were used for filtration and extraction: a C18 filter was used instead of a liquid/liquid extraction and an Accelerated Solvent Extractor (ASE) was used instead of the traditional soxhlet extraction. After pre-oxidation of the sample extract, clean up was done using a multi-layer silica gel column coupled to a carbon column. The PCDD/F and PCB fractions were finally analyzed with the H1L7.5c1 and/or the H1L6.1c3 mouse hepatoma cell lines. The limit of quantification was 1.4 pg CALUX-BEQ m⁻² d⁻¹ for the PCBs and 5.6 pg CALUX-BEQ m⁻² d⁻¹ for the PCDD/Fs, when using the new sensitive H1L7.5c1 cell line. The GC-HRMS recovery for all PCDD/F congeners was between 55% and 112%, with a mean recovery of 90%. CALUX recoveries of spiked procedural blanks were between the accepted ranges of 80-120%. Repeatability and reproducibility were satisfactory and no interferences from metals were detected. The first results from the Flemish measurement program showed good correlation between CALUX and GC-HRMS.     

Contamination and emission factors of PCDD/Fs, unintentional PCBs, HxCBz, PeCBz and polychlorophenols in chloranil in China

The production of chloranil is regarded as a potentially significant source of unintentional POPs. This research aimed to identify the contamination levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HxCBz), pentachlorobenzene (PeCBz) and polychlorophenols in chloranil samples and identify the formation pathways. The toxicity equivalent (TEQ) values for PCDD/Fs in the chloranil samples ranged from 163 to 1 540 200 pg I-TEQ g⁻¹, while the PCB TEQ values ranged from 1.9 to 3.3 pg WHO-TEQ g⁻¹. High levels of HxCBz, PeCBz and polychlorophenols were also detected in the chloranil samples. The average emission factors were 522.2 mg I-TEQ t⁻¹ (PCDD/Fs), 0.0026 mg WHO-TEQ t⁻¹ (PCBs), 32.6 mg t⁻¹ (HxCBz), and 136.6 mg t⁻¹ (PeCBz). The PCDD/Fs and PCBs are thought to be formed from the polychlorophenols and polychlorobenzenes generated during the chloranil production process. Purification of the chloranil products can reduce the unintentional POPs releases and protect the environment.     

Atmospheric bulk deposition of dioxin and furans to Danish background areas

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were measured in bulk deposition at three Danish rural forest sites with a mutual maximum distance of 450 km. At one of the forest sites concentrations in the ambient atmosphere were sampled from a 12 m high tower. Sampling was carried out within a period of 3 years with sampling intervals of 1–2 months. Mean bulk deposition fluxes were 1 ng m⁻² yr⁻¹ I-TEQ and deviated less than 30% between the sites. Yearly average PCDD/F concentrations in the atmosphere were 24 fg m⁻³ I-TEQ with maximum values in the winter period. During winter months atmospheric concentrations of PCDD/F and oxidized sulphur compounds showed a positive correlation, furthermore seasonal bulk deposition showed correlation between PCDD/F and sulphate.     

Polychlorinated dibenzo-p-dioxins,dibenzofurans, biphenyls,paraffins and polybrominated diphenyl ethers in marine fish species from Ebro River Delta (Spain)

The results of a surveillance programme on the determination of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and short chain chlorinated paraffins (SCCPs) in marine fish and shellfish species which are fished, commercialised and consumed in the Ebro River Delta area (NE, Spain) are presented. The study included the analysis of five marine fish species (sardine, gilthead sea bream, conger, eel and flounder) and three shellfish species (murex, carpet shell and mussel) collected in 2012 in five fishing harbours near to this area. WHO-TEQ concentrations for PCDD/Fs and dioxin like PCBs (dl-PCBs) ranged from 0.03 to 0.31 pg WHO-TEQ_2005PCDD/F g⁻¹ wet weight (ww) and from 0.02 to 3.15 pg WHO-TEQ_2005PCB g⁻¹ ww, respectively. All levels were below the maximum concentrations established by the EU Regulation. The PCBs and PCDD/Fs accumulation pattern found in the samples analysed showed a distribution typically reported for marine samples. For marker PCBs and PBDEs, concentration levels ranging from 929 to 57 494 pg g⁻¹ ww and from 36.2 to 827 pg g⁻¹ ww were obtained, respectively, meanwhile for SCCPs levels were between 3.1 and 141 ng g⁻¹ ww. Finally, the trends in the levels of PCDD/F and dl-PCBs found from 2006 to 2012 in fish and shellfish species were studied. A slight decrease of PCDD/F and dl-PCB concentrations was found since 2006.     

Levels of PCDD/Fs,PCBs and PBDEs in breast milk of women living in the vicinity of a hazardous waste incinerator: Assessment of the temporal trend

The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were determined in breast milk from women living in the vicinity of a hazardous waste incinerator (HWI) in Catalonia, Spain. The results were compared with the levels obtained in previous surveys carried out in the same area in 1998 (baseline study), 2002 and 2007. The current total concentrations of 2,3,7,8-chlorinated PCDD/Fs in breast milk ranged from 18 to 126 pg g⁻¹ fat (1.1–12.3 pg WHO₂₀₀₅-TEQ_PCDD/F), while the total levels of PCBs ranged from 27 to 405 pg g⁻¹ fat (0.7–5.3 pg WHO₂₀₀₅-TEQ_PCB). In turn, PBDE concentrations (sum of 15 congeners) ranged 0.3–5.1 g g⁻¹ fat, with a mean value of 1.3 ng g⁻¹ fat. A general decrease in the concentrations for PCDD/Fs, both planar and total PCBs, and PBDEs in breast milk was observed. The levels of PCDD/Fs, PCBs, and PBDEs in milk of women living in urban zones were higher than those corresponding to industrial zones (41%, 26%, and 8%, respectively). For PCDD/Fs and PCBs, the current decreases are in accordance with the reduction in the dietary intake of these pollutants that we have also observed in recent studies carried out in the same area of study.     

Estimation and characterization of PCDD/Fs, dl-PCBs, PCNs, HxCBz and PeCBz emissions from magnesium metallurgy facilities in China

Magnesium production is considered to be one potential source of unintentional persistent organic pollutants (unintentional POPs). However, studies on the emissions of unintentional POPs from magnesium metallurgy are still lacking. Emissions of unintentional POPs, such as polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), polychlorinated naphthalenes (PCNs), hexachlorobenzene (HxCBz) and pentachlorobenzene (PeCBz) are covered under the Stockholm Convention. In this study, these emissions were investigated through a magnesium smelting process. Stack gas and fly ash samples from a typical magnesium plant in China were collected and analyzed to estimate the emissions of unintentional POPs from magnesium metallurgy. Emissions factors of 412 ng TEQ t⁻¹ for PCDD/Fs, 18.6 ng TEQ t⁻¹ for dl-PCBs, 3329 μg t⁻¹ for PCNs, 820 μg t⁻¹ for HxCBz, and 1326 μg t⁻¹ for PeCBz were obtained in 2009. Annual emissions from magnesium metallurgy in China were estimated to be 0.46 g WHO-TEQ for PCDD/Fs and dl-PCBs, 1651 g for PCNs, 403 g for HxCBz and 653 g for PeCBz, respectively.     

PCDDs, PCDFs, dioxin-like PCBs and indicator PCBs in soil from five selected areas in Slovakia

There is a lack of information regarding persistent organic pollutants (POPs) in soil from Slovakia. This paper reports the concentrations of 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), 12 dioxin-like polychlorinated biphenyls (dl-PCBs) and 6 indicator PCBs associated with 32 soil samples collected in 2007 from areas in the vicinity up to several kilometres from four selected industrial PCDD/F sources in Slovakia and one background area.The results show that the total WHO₁₉₉₈-PCDD/F/dl-PCB-TEQ concentrations varied from 0.34 to 18.05 pg g⁻¹ dry weight (dw) and the average total TEQ concentrations in samples collected at the Šala, Košice, Krompachy and Dubová areas were 3.18, 2.64, 7.80, and 3.19 pg g⁻¹ dw respectively. The average of the total WHO₁₉₉₈-TEQ values in three soil samples representing the background Starina area was 0.66 pg g⁻¹ dw. The predominant contaminants among 2,3,7,8-substituted PCDD/Fs, dl-PCB, and indicator PCBs was OCDD, PCB 118, and PCB 153 respectively. The major contributors to the TEQ were 2,3,4,7,8-PeCDF, PCB 126, 1,2,3,7,8-PeCDD, PCB 156 and 1,2,3,4,7,8-HxCDF + 1,2,3,4,7,9-HxCDF in descending order.